Buggy code:
public static ExpressionValue createExpressionValue ( int register , boolean result ) { } public static ExpressionValue createExpressionValue ( int register , float result ) { } public static ExpressionValue createExpressionValue ( int register , String result ) { } public ResultTuple addUnaryNotStep ( int register , ExpressionValue value , ExecutionStep step ) { } private StepFactory . UnaryOperationInformation generateUnaryOperationInfoformation ( int register , ExpressionValue leftValue , ExecutionStep step ) { } private ResultTuple addUnaryOperation ( StepFactory . UnaryOperationInformation info , OperationEnum op ) { } public ResultTuple addBinaryEqualsStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryNotEqualsStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryIsAStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , TypeDescriptor type ) { } public ResultTuple addBinaryGreaterThanStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryGreaterEqualsStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryLessThanStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryLessEqualsStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryOrStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryAndStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryAddStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } private StepFactory . BinaryOperationInformation generateBinaryInfoformation ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } private StepFactory . BinaryOperationInformation generateBinaryInfoformation ( int register , ExpressionValue leftValue , ExecutionStep leftStep , TypeDescriptor type ) { } private ResultTuple addBinaryOperation ( StepFactory . BinaryOperationInformation info , OperationEnum op ) { } private void preBinaryOperationStep ( StepFactory . BinaryOperationInformation info ) { } private ResultTuple postBinaryOperationStep ( StepFactory . BinaryOperationInformation info ) { } public ResultTuple addBinarySubtractStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryMultiplyStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryDivideStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public ResultTuple addBinaryModStep ( int register , ExpressionValue leftValue , ExecutionStep leftStep , ExpressionValue rightValue , ExecutionStep rightStep ) { } public void addAssignmentStep ( LineInformation location , String variableName , ExpressionValue rightValue , ExecutionStep rightStep , boolean localOnly , boolean hasRHS ) { } private StepFactory . AssignmentStepInformation generateAssignmentStepInformation ( LineInformation location , String variableName , ExpressionValue rightValue , ExecutionStep rightStep , boolean localOnly , String variableInObjectName , ClassDescriptor parentClazz , boolean isMe , boolean isValidConstantAssignment ) { } private void addAssignmentGeneralStep ( StepFactory . AssignmentStepInformation info ) { } public void addAssignmentStep ( LineInformation location , String variableName , boolean localOnly , boolean hasRHS ) { } public void addAssignmentStep ( LineInformation location , String variableName , ExpressionValue rightValue , ExecutionStep rightStep , boolean localOnly , String id , ClassDescriptor parent , boolean isMe , boolean hasRHS ) { } public ResultTuple addLoopCounter ( int register , LineInformation location ) { } public ResultTuple addLoopCounter ( int register , ExpressionValue inValue , LineInformation location ) { } private ResultTuple addLoopCounterGeneral ( int register , LineInformation location , ExpressionValue inValue ) { } private ResultTuple addStackMoveStep ( int register , LineInformation location , CallStep call ) { } public ResultTuple addCallStep ( CallInfo info ) { ResultTuple tuple = new ResultTuple ( ) ; String methodKey = MethodDescriptor . autoGenerateKey ( info . methodName , info . argumentTypes ) ; ClassDescriptor clazz = null ; MethodDescriptor method = null ; VariableParameterCommonDescriptor vd = null ; String className = "" ; if ( info . isSoloMethod ) { CompilerError e = this . machine . getSymbolTable ( ) . getControlFlow ( ) . addStatement ( info . location ) ; if ( e != null ) { machine . getCompilerErrors ( ) . addError ( e ) ; } } if ( info . isObjectCall ) { vd = machine . getSymbolTable ( ) . getCurrentScope ( ) . getVariable ( info . variable . getName ( ) ) ; <START_BUG> if ( vd == null ) { <END_BUG> CompilerError error = new CompilerError ( ) ; error . setLineNumber ( info . location . getStartLine ( ) ) ; error . setError ( ( ( "The<seq2seq4repair_space>variable<seq2seq4repair_space>" + ( info . variable . getName ( ) ) ) + "<seq2seq4repair_space>must<seq2seq4repair_space>be<seq2seq4repair_space>defined<seq2seq4repair_space>before<seq2seq4repair_space>it<seq2seq4repair_space>is<seq2seq4repair_space>used." ) ) ; error . setColumn ( info . location . getStartColumn ( ) ) ; error . setErrorType ( MISSING_VARIABLE ) ; error . setFile ( info . location . getFile ( ) ) ; machine . getCompilerErrors ( ) . addError ( error ) ; tuple . setNextRegister ( info . register ) ; tuple . setStep ( new CallStep ( ) ) ; tuple . setValue ( new ExpressionValue ( ) ) ; return tuple ; } else { TypeDescriptor type = vd . getType ( ) ; machine . getSymbolTable ( ) . getCurrentClass ( ) . resolveSubTypes ( type . getSubTypes ( ) ) ; clazz = machine . getSymbolTable ( ) . findFullyQualifiedClass ( type . getName ( ) ) ; className = type . getName ( ) ; if ( clazz == null ) { clazz = machine . getSymbolTable ( ) . findAPrimitivesClass ( type . getName ( ) ) ; if ( clazz != null ) { className = clazz . getName ( ) ; } } } }

Fix:
if ( ( vd == null ) || ( ( vd != null ) && ( ( vd . getType ( ) ) == null ) ) ) {